Question

A train covers a distance of 670 km in 6 h 5 min. If it covers the first 390 km of the
journey at 90 km/h, find its speed for the rest of the journey.
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Answer 1

Answer:

total distance is 670km

total time is (6+5by60)hr

=(6+1by12)hr

= 73/12 hr

then 1st case .

distance is 390km

speed is 90km/hr

then time will be 390/90

= 13/2 hr.

2nd case for the rest of the journey.

distance will be. 670-390 is 280km

time will be. (73/12) - (13/3) = (73-52)/12 = 7/4 hr

thn speed for the rest of the journey will be distance by time

=>. 280by 7/4

=>. (280 X 4 )/7

=>. 160km/hr(Ans).